"Even if you don't use OpenBSD, you're likely to be benefiting from it unknowingly. If you're using Solaris, SCO UnixWare, OS X, SUSE Linux, or Red Hat Enterprise Linux, chances are you're using the OpenBSD-developed OpenSSH for secure shell access to remote machines. If so many are using this software, why are so few paying for it? Official responses (and non-responses) from Sun Microsystems, IBM, Novell, and Red Hat are below, but if you're one of the freeloaders who hasn't contributed to OpenBSD or OpenSSH, what's your excuse?"